Friday, September 13, 2013

Project: Red Rocket - Alive and Driving

Its been a busy six weeks since my last post for the Eclipse. I left you with a car that was running - barely. It would overheat, wouldn't shift into 2nd and wouldn't pull full power. Well, after a few new parts, some troubleshooting, and a lot of elbow grease, she is up to full power! It turned out that getting it running was only the first half of the battle. Read on after the jump to see the completion of the project.

The Red Rocket makes is debut on Main Street.

I started work with the assumption that the overheating problems would go away as the system self-bled with more heat cycles, so I focused on the lack of power. Boost leaks are common on old turbo cars due to rotted or cracked hoses. This is fairly easy to check for. I built an adapter for $8 out of rubber plumbing adapters and a tire valve stem that would allow me to pressurize the intake system.

This adapter connects to the turbo inlet, allowing you to pressurize the intake system with a standard tire inflater.

I attached my air line and put 15psi into the turbo and was rewarded with a PPPPPSSSSSSSFFFFFFTTTTT!!! Using a cheap spray bottle, I squirted soapy water around the line making noise until bubbling gave away the leak point. Lucky for me, it was a loose band clamp and the leak was fixed with an 8mm socket. I was able to charge the system up to 20psi after that, so one problem checked off the list.

The car felt much smoother after that fix, but would not rev above 4000rpm, almost as though it had hit a rev limiter. At least its not overheating anymore. Once again, back to basics: the engine is either missing air, fuel or spark. I just checked the air, so that's good. Time to check fuel. The pump is brand new, so I know its good, but maybe its getting poor signals from the ECU? A voltmeter shows 6.7v at the pump connector, barely half of the proper 12v. The output at the relay, by the ECU, is the full 12v, so it must be voltage drop along the wire. I replace the wire with some 10 gage wire from the hardware store, and everything measures 12v. Another problem, solved.

This is the test apparatus for the ignition power transistor. The circuit should close when 1.5v are applied.

Once again, the car pulls stronger, but halts at 4000rpm. How many different ways can this car be limited to 4000rpm? Some online research leads me to the power transistor for the ignition system. They can be checked using a 1.5v battery and an analog volt meter. This one is bad, but the good news is they're cheap to replace. Yet another problem solved.

Alright, one more pull to see if she's fixed...and she stops at 4k again. WTF?!?! I have verified and fixed 3 separate issues and have not solved the problem. Now I'm pretty ticked off, how the hell was this car even running long enough for the timing belt to have hopped off on the previous owner? Oh well, back to the internet for some research. The last two components that control the engine speed are the ignition coil pack and throttle position sensor. The coil pack Ohms out correctly according to my multimeter, so it looks like the position sensor is the final culprit. It turns out to be an easy replacement with some tricky adjustment, but I get it done pretty quick.

Then I find a small puddle of coolant under the radiator. Damn it, why does this car hate me? Another parts order gets me a new radiator and lower hose. At least there aren't any wires involved in this fix. Finally, I'm ready to give the Red Rocket another test. With fingers crossed, I push the gas pedal. She climbs to 4k, and keeps going! All the way to 7500, she pulls strong! Finally!

The very nice taper on the right side of the gear should not be there. It should be square like the left side. This is the result of using shift cables that were too short.

Rebuilding the transmission requires some expensive tools that I do not want to purchase, so I decide that this is a job for my mechanic. It turns out parts are impossible to find, so the only option is to replace the entire transmission. We opened up the old transmission anyway, just to check out the insides. Several gears were worn and ground out of shape. It looks like the incorrect shift cables that were on the car when I bought it had been there a long time and half engaging gears had taken its toll. The new transmission works perfectly, and I replaced the clutch while we were at it, so the car feels much better.

Well, that's it then. It took 6 weeks long than planned - 4 months total, but the Eclipse is in good running condition. There's even rumors of another SCCA Rallycross to be hosted soon. Back near the beginning of this project, I posted a spreadsheet tabulating all of the costs of the build. The final bill came out to $7,689. Parts were $4k and labor was $1700, even though I did most of the work myself. I could have purchased a running GSX in great condition for $5k, so this was definitely not a good investment, but I now have a practically new car and I know everything about it. Its an excellent platform for a race car build. Maybe I'll start by scavenging the larger brakes from a later model junkyard Eclipse...